Point Loma

Geology:

Point Loma is part of the Point Loma Formation, near the coastline of San Diego. According to the second citation, “The massive, ungraded sandstones in the Point Loma Formation have sharp upper and lower contacts, thick lenses of mudstone clasts, and common load-deformation structures, suggesting deposition largely by grain-flow processes.”

Paleontology:

The Upper Cretaceous strata in the Point Loma formation contain abundant trace fossils of the species Qphiomorpha and Thalassinoides, which suggest that the area was a shallow sea during the Cretaceous Period.

Directions:

According to The Fossil Forum (Citation 1), “Towards San Diego, get off at the Tecolate Road/Sea World exit. Proceed west on Sea World Drive — past Sea World, it becomes Sunset Cliffs Blvd. Drive to the end of Sunset Cliffs and park in the lot for Sunset Cliffs Park. Look along the top of the sea cliff.”

Works Cited:

Gary Kindel, “Fossil Collecting Sites in North America,” (Digital Rockhound’s Companion Site 2009) http://www.digitalrockhound.blogspot.com

Philip Kern et al, “Trace Fossils and Bathymetry of the Upper Cretaceous Point Loma Formation, San Diego, California,” (San Diego State U, Rice U 1974) http://gsabulletin.gsapubs.org/content/85/6/893.abstract

 

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Coal Point, Isla Vista

Geology: The fossiliferous layers are part of an unnamed Pleistocene formation. Once you park, walk down to the beach and look for the sedimentary rocks on the beach cliff. However, the geology of the area should be similar to the Monterey formation which contains both Gaviota Beach, and Jalama Beach.

Fossils: The layers of sandstone contain marine assemblages from the Pleistocene epoch.

 

Jack’s Peak County Park

Geology: According to the USGS, “Geophysical data and sea floor samples collected from the continental shelf and slope between Ano Nuevo Point and Point Sur, California indicate that the Monterey Bay region has had a complex late Cenozoic tectonic history”, meaning that it is difficult to easily date the fossils based on location. See the Further Reading to learn more about the geology of the Monterey Bay region.

Fossils: Fossils containing small leaves and shells are in shale a hundred yards down the trail from the west parking lot.

Further Reading/Works Cited:

Gary Greene, “Geology of the Monterey Bay region, California” (USGS 1977) https://pubs.er.usgs.gov/publication/ofr77718

Scotts Valley

Geology: Being within the Santa Cruz Mountains in the Central Coast Ranges, Scotts Valley is a geologically active region under the influence of multiple fault lines. The valley’s bedrock is part of the Purisima Formation. Fossils obtained in the area are likely part of the Santa Margarita Sandstone. According to the Scotts Valley Town Center, “The Santa Margarita Sandstone generally consists of massive, fine- to medium-grained sandstone of upper Miocene geologic age. The Santa Margarita Sandstone forms a distinctive formation of white and yellow sand that can be observed in cliffs around the area”.

Paleontology: Marine fossils are very prevalent in the area, and it is a common area for fossil collectors to visit. Shark teeth (Mako, Megalodon, etc), dolphin, whale, sea cow, and walrus bones, and sand dollars have been found in the area. Sand dollars are especially common and should be fairly easy to spot. Here is a collection of photos of fossils recovered from the area from the Land Trust of Santa Cruz County. Recently, a four million year old whale fossil was discovered in the area. The find was covered by the article, “Whale Fossil Uncovered in Scotts Valley”.

Directions to Sand Dollar Site: One site in particular is known for its abundance of sand dollars. According to this fossil collector, Take Hwy 17 south from San Jose towards Santa Cruz/Scotts Valley. Take Mount Hermon Exit in Scotts Valley. Turn right onto Scotts Valley Drive. Turn right onto Bean Creek Road, and drive a little over a mile until you see a tall, sandy roadcut that is fairly steep. However, it is important that the area is off limits, and you will encounter ‘No Trespassing’ signs.

Works Cited:

RMcWilson, “Fossil Sand Dollar Site in Scotts Valley, California,” (Flickr 2009)

“Scotts Valley Town Center Specific Plan EIR, 4.5 Geology and Soils,” (City of Scotts Valley)  http://www.scottsvalley.org/downloads/town_center/4.5%20Geology%20and%20Soils.pdf